A. Coke Pellets Produced According to the Present Invention Versus Slot-Oven Coke for Blast Furnace Use
This invention is directed to apparatus and a method for agglomerating and controlling the size consist of an agglomerating material formed in a balling or rotating drum. More particularly, though not limiting in its application, this invention is directed to the agglomeration of carbonaceous material to form pellets of a relatively uniform size. When the pellets are formed and calcined, they may be used in place of metallurgical coke in the operation of a blast furnace. For convenience and to describe the further aspects of this invention, the description to follow will be directed to apparatus for, and a method of, forming such pellets.
Large quantities of coke are required annually by the steel industry for the manufacture of blast furnace iron, which, in turn, is converted into steel. Today, coke suitable for use in a blast furnace requires a mixture of high- and low-volatile coals (preferably having a low sulfur and low ash content) that is capable of being coked. Furthermore, such coals must be coked in slot-type by-product coke ovens, which create serious air and water pollution problems. The present invention relates to apparatus and a method for forming relatively uniformly sized pellets of carbonaceous material which may be further treated to form coke pellets having characteristics that make them suitable for use in place of slot-oven coke in a blast furnace.
The coke pellets, or agglomerates, formed by incorporating into a coke-pellet process the agglomerating method and apparatus described in the present invention have the characteristics required for satisfactory functioning in a blast furnace. That is, they supply the necessary heating value to the melting process and are strong enough to sustain the furnace burden. The pellets retain their physical integrity and resist crumbling, thereby permitting the passage of the ascending hot gases through the overlying burden.
Inasmuch as the present invention deals with the agglomerating step in a known process for making coke pellets, or agglomerates, it may be helpful to summarize the general characteristics of such process.